has any company ever made "hi-fi" plastic cased speakers?

[dshreter]

So it can well be done but is it case of plastic being more expensive per pound than MDF?

Or is it because plastic mouldings require expensive injection machines that isnt needed on MDF?

It's more the latter than the former. High quality injection molding infrastructure is expensive, and requires high quantities to pay off the cost of the molds. MDF can be cut by computer-controlled tools and can shift from one design to another with comparative ease.

But then a slew of companies inc. Behringer can injection mould plastic PA units like the PK108 as active and passive for a reasonable price?

This is true, but there are a couple reasons. Behringer will probably use that same mold to sell a zillion of those for a decade, not refresh the design every other year. There is also wide variation in the quality of construction, and it is more difficult and expensive to product heavy injection molded plastic than with thin walls. The KH80 which is a tiny speaker has quite a robust shell and bracing.

Neumann KH80DSP Teardown

A friend of mine decided to look at the inside of the KH80DSP because he found the Neumanns run hotter than his JBL LSR305P MkII. Seems like there hasn't been any teardown picture of the KH80DSP on the internet. My friend kindly allowed me to share these disassembly pictures on this forum, so...

www.audiosciencereview.com

So then I cant see why aluminium has been used in some cases when plastic could be cheaper??? (ie. genelecs)

Because there is a customer segment that is willing to pay for aluminum. It is quite rarely used for this purpose because it is expensive.

 

[kemmler3D]

Plastic is less prominent in hifi speakers for two reasons I know of:

High quality injection molding infrastructure is expensive, and requires high quantities to pay off the cost of the molds.

Can't emphasize this enough. The cost to build an injection mold for a serious hifi speaker is around $250K minimum and could run to the millions for larger ones. $250K will buy you a whole wood shop and someone to run it for a year (give or take) so the choice is easy for smaller-run manufacturers.

Also, injection molding isn't well-suited for very thick pieces of plastic. The cooling takes longer, things warp, etc. So for hifi it's a less obvious process to use.

Plastic also generally has lower stiffness than MDF or wood. So you need thicker plastic than wood to get the same cabinet performance. This makes injection molding even harder. You can mitigate this using more complex bracing and curved shapes and things with plastic, but it's still not a 1:1 replacement for MDF.

For PA, sound leakage from around the cabinet is a less big deal, the enclosures tend to have simpler internal structures, and they tend to sell more units per model, so it works.

There is also some marketing logic in this beyond the practical considerations. Some home hifi speakers probably would make sense in plastic. However, hifi buyers see plastic enclosures as low-fi, and so you have to consider that you'll need to price lower or accept lower sales of a plastic enclosure... leading to a self-fulfilling prophecy in which "hifi doesn't use plastic enclosures".

 

[Sokel]

Plastic is less prominent in hifi speakers for two reasons I know of:


Can't emphasize this enough. The cost to build an injection mold for a serious hifi speaker is around $250K minimum and could run to the millions for larger ones. $250K will buy you a whole wood shop and someone to run it for a year (give or take) so the choice is easy for smaller-run manufacturers.

Also, injection molding isn't well-suited for very thick pieces of plastic. The cooling takes longer, things warp, etc. So for hifi it's a less obvious process to use.

Plastic also generally has lower stiffness than MDF or wood. So you need thicker plastic than wood to get the same cabinet performance. This makes injection molding even harder. You can mitigate this using more complex bracing and curved shapes and things with plastic, but it's still not a 1:1 replacement for MDF.

For PA, sound leakage from around the cabinet is a less big deal, the enclosures tend to have simpler internal structures, and they tend to sell more units per model, so it works.

There is also some marketing logic in this beyond the practical considerations. Some home hifi speakers probably would make sense in plastic. However, hifi buyers see plastic enclosures as low-fi, and so you have to consider that you'll need to price lower or accept lower sales of a plastic enclosure... leading to a self-fulfilling prophecy in which "hifi doesn't use plastic enclosures".

Then again Rockport which is high praised amongst hi end community (and rightfully so for me based on look,feel and wow sound) proudly states that their recipe for this heavy,riggit cabinets is fiber glass,polyurethane and stuff like that.

Edit:
Here some photos of the step by step construction of their 140.000 euro Orion:

My Favorite New Ultra Product from Munich's High End 2022: Rockport’s Orion Loudspeaker

 

[Weeb Labs]

The IK Multimedia iLoud MTMs and Micro Monitors both make use of plastic cabinets.

 

[waynel]

It's more the latter than the former. High quality injection molding infrastructure is expensive, and requires high quantities to pay off the cost of the molds. MDF can be cut by computer-controlled tools and can shift from one design to another with comparative ease.


This is true, but there are a couple reasons. Behringer will probably use that same mold to sell a zillion of those for a decade, not refresh the design every other year. There is also wide variation in the quality of construction, and it is more difficult and expensive to product heavy injection molded plastic than with thin walls. The KH80 which is a tiny speaker has quite a robust shell and bracing.

Neumann KH80DSP Teardown

A friend of mine decided to look at the inside of the KH80DSP because he found the Neumanns run hotter than his JBL LSR305P MkII. Seems like there hasn't been any teardown picture of the KH80DSP on the internet. My friend kindly allowed me to share these disassembly pictures on this forum, so...

www.audiosciencereview.com

Because there is a customer segment that is willing to pay for aluminum. It is quite rarely used for this purpose because it is expensive.

B&W DM302 speakers were largely made of plastic. https://www.stereophile.com/standloudspeakers/542/index.html

 

[dshreter]

Plastic also generally has lower stiffness than MDF or wood. So you need thicker plastic than wood to get the same cabinet performance. This makes injection molding even harder. You can mitigate this using more complex bracing and curved shapes and things with plastic, but it's still not a 1:1 replacement for MDF.

The IK Multimedia iLoud MTMs and Micro Monitors both make use of plastic cabinets.

B&W DM302 speakers were largely made of plastic.

Yep, as kemmler 3D said, it is very expensive to make large injection molded parts, and there is also a tendency for warping that becomes harder to manage. That's why you see it primarily on smaller speakers or design elements.

This is the type of infrastructure required to mold a car bumper, which is give or take similar in size to a floorstanding speaker. You can imagine this is extremely expensive and not practical for speaker manufacturers to have these kinds of facilities.

 

[Phantomuser]

Devialet speakers are plastic...and sound fantastic.
I couldn't resist

 

[dshreter]

Then again Rockport which is high praised amongst hi end community (and rightfully so for me based on look,feel and wow sound) proudly states that their recipe for this heavy,riggit cabinets is fiber glass,polyurethane and stuff like that.

Edit:
Here some photos of the step by step construction of their 140.000 euro Orion:

My Favorite New Ultra Product from Munich's High End 2022: Rockport’s Orion Loudspeaker

I wonder why they add a carbon fiber shell when it has a (stiff) aluminum frame. It's like if Genelec wrapped their speakers in carbon fiber.

 

[Sokel]

I wonder why they add a carbon fiber shell when it has a (stiff) aluminum frame. It's like if Genelec wrapped their speakers in carbon fiber.

I suppose that they take it to extreme as this is one of their top models,and high end is about extremities.
Their much more affordable Atria II (about 35.000 euro/pair street price) must be much more simple although it's finish is absolutely top too.

 

[chelgrian]

Plastic is less prominent in hifi speakers for two reasons I know of:


Can't emphasize this enough. The cost to build an injection mold for a serious hifi speaker is around $250K minimum and could run to the millions for larger ones. $250K will buy you a whole wood shop and someone to run it for a year (give or take) so the choice is easy for smaller-run manufacturers.

Also, injection molding isn't well-suited for very thick pieces of plastic. The cooling takes longer, things warp, etc. So for hifi it's a less obvious process to use.

Plastic also generally has lower stiffness than MDF or wood. So you need thicker plastic than wood to get the same cabinet performance. This makes injection molding even harder. You can mitigate this using more complex bracing and curved shapes and things with plastic, but it's still not a 1:1 replacement for MDF.

For PA, sound leakage from around the cabinet is a less big deal, the enclosures tend to have simpler internal structures, and they tend to sell more units per model, so it works.

There is also some marketing logic in this beyond the practical considerations. Some home hifi speakers probably would make sense in plastic. However, hifi buyers see plastic enclosures as low-fi, and so you have to consider that you'll need to price lower or accept lower sales of a plastic enclosure... leading to a self-fulfilling prophecy in which "hifi doesn't use plastic enclosures".

The other thing to note is more expensive and thus lower run PA tends to be made of Baltic Birch Ply for exactly the reasons you state they would never make the money back on the setup to cast any other material.

Cheaper but much higher run boxes even the ones made by QSC, Yamaha etc are ABS plastic.

However even in the PA market it's engrained that 'wood sounds better than plastic' even though it's a self fulfilling prophecy. It would be entirely possible to make a high performant non-wood PA speaker it would just be more expensive than making it of birch ply.

 

[Anonamemouse]

My bass cabinets are made from sewage drain pipe. Nothing plasticy about that sound...

 

[kemmler3D]

Yep, as kemmler 3D said, it is very expensive to make large injection molded parts, and there is also a tendency for warping that becomes harder to manage. That's why you see it primarily on smaller speakers or design elements.

This is the type of infrastructure required to mold a car bumper, which is give or take similar in size to a floorstanding speaker. You can imagine this is extremely expensive and not practical for speaker manufacturers to have these kinds of facilities.

VERY few audio companies would own their own injection molding plants (maybe Sony, Bose, etc... ) exactly for this reason. Plants that DO own this type of equipment aren't going to take your calls unless you're doing a whole lot of units ... 50K per order, maybe? Just like it's expensive to make the molds, it's time consuming and expensive to set them up. So there is a high barrier of entry to doing mass production of plastic parts at this size.

Rockport is probably cast parts instead of injection molded, or something. At very small quantities (say 1000 per year) I imagine this can be practical and you do resins and other interesting things that don't work on standard injection molds.

So then I cant see why aluminium has been used in some cases when plastic could be cheaper??? (ie. genelecs)

Aluminum can generally be cast or machined.

The problems with casting aluminum are similar to injection molding.

The problem with machining aluminum is you have to take a solid block of aluminum and carve it down. This is a one-at-a-time process, fairly slow, and the material is super-expensive.

Aluminum is great for speakers but again, unless you can afford the equipment to pop the housings out of a mold, you're looking at a much higher unit cost than MDF for a moderate-at-most improvement in performance.

 

[kemmler3D]

I wonder why they add a carbon fiber shell when it has a (stiff) aluminum frame.

Probably marketing / aesthetics. People see carbon fiber and they think "high performance" regardless of whether it makes sense.

 

[dfuller]

this is not a new thing... I remember sneering at the infamous Yamaha NS10 with my hifi buddies as not being "hi-fi" literally decades ago

Well, in fairness, the NS10 is certainly not high fidelity lol.

 

[jhaider]

NHT Xd was largely made out of something called “bulk molding compound.” That sounds like a fancy plastic to me.

NHT Xd active loudspeaker system

NHT's Xd system is what audiophiles have been saying they want: a matched loudspeaker system that optimizes the performance of its components for a real-world domestic listening environment. But with their dollars they've voted against just such systems for years. If we put our money where our...

www.stereophile.com

 

[DanielT]

Considering that 3D printers are becoming more common, I can suspect that more constructions similar to this will appear:

That was in and of itself a DIY project, but still.

 

[voodooless]

You can imagine this is extremely expensive and not practical for speaker manufacturers to have these kinds of facilities.

They don’t have to. Generally these things are at companies that do injection molding all day long. They manage the molds and production and by doing so can occupy the machines basically 24/7. That is really the only way to make this economical.

 

[Putter]

My bedroom system has Infinity Infinitesimal Four speakers. They have an EMIT-R tweeter and 5.75 inch 'mid woofer' and a plastic body and metal screen. I think they sound pretty good with the help of a sub for the low end.

​

 

[dshreter]

They don’t have to. Generally these things are at companies that do injection molding all day long. They manage the molds and production and by doing so can occupy the machines basically 24/7. That is really the only way to make this economical.

True, though just the mold of that size is extremely expensive.

 

[Tonygeno]

Neumann KH80. Ok, that's not HiFi.

So is it LoFi?